Do SC engines drive like S engines?

[andrew15]

Maybe clouding the issue, but:
Really, what would be the difference between say a 2.7 RS spec engine and a 3.0L with Early S cams (and appropriate pistons / carbs)?

Basically it's only 10% larger displacement and has the same stroke:
Is that really enough to call the 3.0 torquey and not as peaky?
Was the step from 2.0/2.2S to 2.7 RS also a big decrease in peakiness with an increase in torque?

AM

[klaucke]

Andrew, the difference is in the crank. The SC 3.0 Crank is heavier enough to make the car slower revving, and not as "alive" feeling. A Carrera 3.0 uses the 2.7 crank and thus can retain that early, lively, free revving feeling. This is all from what I read on the forum, and my own logic. I've never driven an SC or C3. I guess it's Carrera 3.0 or earlier for making an early feeling engine.

[andrew15]

Could this be partially offset by using a lightweight flywheel?

[Bobboloo]

Lightweight flywheel, rods, and pistons can all contribute to a rev happy motor. I don't see why you couldn't make a 3.0SC based motor at least as rev happy as a stock 2.4 or 2.7RS.

[Shaun @ Tru6]

Originally posted by andrew15
Could this be partially offset by using a lightweight flywheel?

I don't have pound vs. pound #'s, but I'm guessing an Al pressure plate will net more weight savings than a lightened flywheel.

The 2 together, that's sure to make a difference.

[targa911S]

Early S cars like to run where the air is thin. Around town I rarely get into 4th gear. The cams come on crazy at about 4400 rpm and it starts to make the sweetest sound you have ever heard all the way to 7200 rpm, pulling hard all the way. They are really crabby when you hold them back. They have two speeds..idle, and Holy ****e! By comparison the SC is very gentlemanly, and civilized.

[cashflyer]

I have GOT to drive some more 911s!!

I've got a 78 SC; 3.0L; CIS. I know it has SSI header/exchangers, and has been re-cammed. But that is all I really know about the work the PO did to it. Let me say, it screams compared to almost everything else I have owned.

Now, reading this thread, I want to drive some others to get a real comparison!!

[svandamme]

Originally posted by andrew15
Maybe clouding the issue, but:
Really, what would be the difference between say a 2.7 RS spec engine and a 3.0L with Early S cams (and appropriate pistons / carbs)?

Basically it's only 10% larger displacement and has the same stroke:
Is that really enough to call the 3.0 torquey and not as peaky?
Was the step from 2.0/2.2S to 2.7 RS also a big decrease in peakiness with an increase in torque?

AM

there's several things involved
- more displacement = more low end grunt
the peakyness of the cams is less obvious on larger displacement engines

- MFI throttle response

2.2S to 2.7 RS is definately a big decrease of peakyness

even 2.4 to 2.7 differs a great deal :

[JeremyD]

I've driven an S - and I have to say that my 3.4 drives much more like an S than my 3.2 carrera used to.

almost a stumble down low - but boy when the 993 ss cams come on line there is a rush towards redline - unfortunately kept below 5000 rpms at break in - but you can tell she is coming into her own at 5000 rpms. Can't wait to take the training wheels off.

[KobaltBlau]

Originally posted by Todsimpson
I originally built my RS replica with a 2.2S, later I put in a euro 3.2 with SSI's and 964 cams.

The car is faster and more reliable now but it's missing some of the fun.

It's a lot of work to keep that little motor on the cam but the rush from 4500 rpm on up is very, very cool.

what gearbox do you have, Tod?

Originally posted by JeremyD
I've driven an S - and I have to say that my 3.4 drives much more like an S than my 3.2 carrera used to.

almost a stumble down low - but boy when the 993 ss cams come on line there is a rush towards redline - unfortunately kept below 5000 rpms at break in - but you can tell she is coming into her own at 5000 rpms. Can't wait to take the training wheels off.

Did camgrinder suggest the 993ss cams? Can you elaborate on "almost a stumble down low"?

TIA

[donstevens]

Originally posted by svandamme
there's several things involved
- more displacement = more low end grunt
the peakyness of the cams is less obvious on larger displacement engines

- MFI throttle response

2.2S to 2.7 RS is definately a big decrease of peakyness

even 2.4 to 2.7 differs a great deal :

That is a very cool illustartive graph. The difference between my 98 pound weakling 2.4T and a 2.7RS is astonishing. No wonder that was such a popular configuration.

Don

[JeremyD]

Originally posted by KobaltBlau

Did camgrinder suggest the 993ss cams? Can you elaborate on "almost a stumble down low"?

TIA

Just like the "S" where it sort of collects itself - not really a stumble - more like a "i'm starting to accelerate" ... difficult to put in words - it's not really a fault - just a driving characteristic - just like the "S" that I drove (only driven one btw)

No camgrinder did not recommend them (the cams) He was great to work with - measured everything for me, made recommendations on rockers and such, in fact I just went to John and said, this is what I want... I got the recommendation for the 993 ss cams if I would do the exhaust too from several sources, especially not having to be emmission compliant.

[Todd Simpson]

My current trans is a 7:31 mag case 915, no LSD. With the 2.2S I used a 901 (911) also no LSD.